HR: 0800h
AN: GP11D-0865 [Abstracts]
TI: Paleomagnetic Reversal Frequency in the Lorne Lavas of Western Scotland and their Implications for
Eruption Duration
AU: * Mitchell, E
EM: es0u113d@liv.ac.uk
AF: University of Liverpool, Department of Earth and Ocean Sciences, University of Liverpool,, Liverpool,
L69 3GP
United Kingdom
AB:
The Lorne Lavas of Western Scotland are a sequence of approximately 400 million year old basalts and basaltic andesites. A
previous paleomagnetic study, undertaken in 1974, of randomly selected sites within the lava pile found the same polarity in
all samples. This current work aims to resample the lava flows in a temporal sequence and to apply modern paleomagnetic
techniques to look for paleofield reversals. The aim of this study is to constrain the time period over which these lavas
were erupted. These results will also be integrated with a geochemical study of the lavas currently being undertaken in the
department. A sub-study of anisotropy of magnetic susceptibility (AMS) will aim to deduce paleoflow directions in an attempt
to determine whether the flows were erupted from a central vent or from numerous fissures. This poster will present
preliminary data and interpretations from thermal demagnetisation and AMS measurements from approximately 20 sampling sites
throughout the lava pile.
DE: 1518 Magnetic fabrics and anisotropy
DE: 1535 Reversals (process, timescale, magnetostratigraphy)
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2004 AGU Fall Meeting